Author Archive

Will Enough Young People Sign Up?

The Obama administration hopes that 40% of enrollees in the new health care exchanges will be between the ages of 18 and 34. The worst outcome would be 40% enrollment of older people (age 55 to 64). According to The New York Times, that unfortunate outcome is occurring in many states. Here are the counts in states reporting so far:

  • The ratio of older enrollees to younger ones is 2 to 1 in Colorado, Connecticut, Rhode Island, Washington, and Minnesota.
  • The ratio of old to young is 1½ to 1 in California and Kentucky.
  • Only in Maryland and Massachusetts do the number of young exceed the number of older enrollees.

The ratio of 2 older enrollees for 1 younger one does not give the real flavor of the age skew in Colorado, where as of November 30, 43 percent of enrollees were over age 55, and 61 percent were over age 45. Just 17 percent are aged 18 to 34.

No one knows the health status of exchange enrollees. Connect for Health Colorado, one of the more successful state exchanges, says that 15,074 people had enrolled as of December 9. The problem is that this is only 177 more Coloradans than were enrolled in the state and federal plans for the uninsurable, plans that are ending soon.

Dec 17, 2013 | 11 comments | by

Testing Without Theory

From time to time I run across a finding in the medical literature along the lines of “Coffee Causes Bladder Cancer.” Or was it “Coffee Prevents Bladder Cancer”? Oops, maybe it wasn’t coffee at all. Maybe it was broccoli. Or cashew nuts.

I rarely ever report these results at my blog, with the possible exception of vitamin studies and I even regret reporting on those.

Many of these studies have the same basic problem: They involve testing without theory. Give me one group of people who drink coffee, another group that abstains and, say, several hundred health and demographic variables and I can almost guarantee you that coffee drinking (or not drinking) will correlate with something. It will probably correlate with 4 or 5 things.

The literature on spurious correlation has a number of entertaining examples of this. In one study (described here), the prices of a select list of NYSE stocks rose 87 percent of the time when the temperature reading fell at a weather station on Adak Island, Alaska. The authors note that with 3,315 stocks, chance alone insured that some were sure to be correlated with temperature measurements.

As for statistical significance, remember what a 95% confidence interval means. It means that 5% of the time, the relationship you have discovered could have been produced by random chance. If you have thousands of researchers mining thousands of data sets, they are almost guaranteed to find many spurious relationships and, unfortunately, they will get them published in peer reviewed journals as scholarly papers. The results will then appear in daily newspapers (what editor can resist a finding that coffee causes or prevents any malady?), and the public will be sorely misled.

The New Math 

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May 29, 2012 | 13 comments | by

Does Lack of Insurance Cause Premature Death? Probably Not.

Truth is not only the first casualty of war, it is also the first casualty of serious public policy debate.

“An estimated 17,000 children in the United States might have died unnecessarily over nearly two decades because they didn’t have health insurance,” said U.S. News and World Report. “The authors estimated that at least 1,000 hospitalized children died each year simply because they lacked insurance,” said The New York Times.

They’re talking about a Johns Hopkins Children’s Center study [gated, but with abstract]. But between the media hype and the actual study is an enormous chasm that separates fact from fiction. In truth, the authors of the study did not establish that anybody, anywhere, died of any cause whatsoever because of a lack of health insurance.

This is only the latest in a series of ridiculous claims that have been injected into the health insurance debate. What follows is a brief review, some of which has appeared earlier at the Health Affairs blog.

It’s life’s illusions I recall

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Nov 02, 2009 | 36 comments | by